Here's one bit of good news: You don't have to worry about being sentenced to stoning in Oklahoma anymore. The odds were never great that stonings were going to happen in a state famous mostly for wheat, beef and college football, but still, who needs that worry? So Oklahomans went to the polls on Nov. 2 and in a squeaker of a vote  70% to 30%  approved a constitutional amendment preventing the state's courts from ever imposing Islamic Sharia law.

"Oklahoma does not have that problem yet," said state Senator Rex Conrad, author of the bill. "But why wait until it's in the courts?" Oklahoma, for the record, does not yet have the dunking stool or mandatory leeching either. Perhaps they can keep till the 2014 midterms. (See 30 Mosques in 30 Days.)

As Oklahoma goes, so goes the nation  or at least Murfreesboro, Tennessee, where residents have been trying to block the construction of a proposed mosque to prevent the same kind of Islamic tidal wave the Oklahomans see coming. "I'm all about freedom of religion," said Lt. Gov. Ron Ramsey. "But you cross the line when they try to start bringing Sharia Law here to the state of Tennessee."

On Nov. 17 a judge ruled that the mosque construction could go ahead, but that decision is on appeal. The Oklahoma amendment is similarly tied up in the courts, with a hearing before a federal judge set for Nov. 22.

None of this can be easy for America's 2.5 million Muslims, who have had a hard enough time since Sept., 2001. But if nothing else, they can at least remind themselves they're not alone. In 2008 and 2006, it was illegal immigrants who emerged as the election cycles' designated bad guys. In 2004, it was gays and lesbians  specifically, gays and lesbians who wanted to get married. In that cycle alone, 11 states passed anti-gay marriage amendments, bringing like-minded voters to the polls who picked like-minded candidates.

This sudden fungibility of America's electoral bogeymen is a curious turn. The strategy of designating an alien "other" for political ends is hardly new in human history, and over the centuries it has been employed with equal expediency by the left and the right. But once a go-to ghoul has been established, the casting tends to stay fixed for a while  think Catholics vs. Protestants, Sunnis vs. Shi'ia, Indians vs. Pakistanis. In the U.S. too, African Americans were used as a cultural wedge group by political operators for the better part of 150 years. So why these suddenly revolving target groups, and what does this suggest not just about politics, but about human behavior?

The affiliative impulse is not a rational thing. We are all hardwired to bond tightly to our own group and to be suspicious of other groups, and in the wild that had survival value. If you're a proto-human living on the savannah, you're less likely to be killed or eaten by a member of your own tribe than by a member of another.

"The features that define a group vary a lot, but once they are defined you prefer your own," says developmental psychologist Yarrow Dunham of the University of California at Merced. "When someone belongs to your group, you like that person better too."

But the particular features that signify group membership can be manipulated, and along with them, fear of people who don't have those features. Here mischief can be made. Yarrow likes to cite a study he conducted in which pre-schoolers were divided into two groups  one given red t-shirts to wear, the other blue. They were all then read stories about both groups. When the kids were asked later what they recalled about the stories, they showed an odd selectivity, remembering mostly the details in which characters wearing their color shirts did good things  and characters wearing the other color did bad things.

What makes those results especially troubling is that t-shirt color is an entirely neutral variable, one that says nothing substantive about the wearer, and yet it quickly became a code for goodness or badness. In the real world, xenophobia is much easier to manufacture because there are often kernels of truth mixed in with the malice. Islamic extremists have done terrible things around the world in recent years; illegal immigration is undeniably a national problem. It doesn't take much of this kind of yeast to make a larger lie rise.

"We saw this especially right after 9/11," says Dunham. "People were driven by fear, by the need to do something. We have a fear muscle and it can overreact."

That, however, doesn't entirely explain the head-snapping way our designated demons have been changing identities lately. Part of it, surely, is a question of the power of the target group itself. It was a lot easier to marginalize blacks or gays before blacks and gays stood up and pushed back. "In a liberal democracy like ours, it's hard to stigmatize a group for too long," says Dunham. "Cultural forces just work against it."

As that happens, a sense of what's culturally fashionable  or, less cynically, culturally decent  makes bias less acceptable. Dunham says he was particularly struck when former President Bush commented recently that one of the lowest points in his life occurred in the wake of the Hurricane Katrina debacle, when Kanye West accused him of racism. Even people who were rightly furious at Bush for his handling of Katrina saw that as a low blow, and his remarks about the pain it caused him had the ring of sincerity to it.

The other big driver of America's ever-changing cast of bad guys is, as with so many other things, the Internet and the 24-hr. cable news cycle. In a total-saturation information environment, it's a simple matter to launch a few rumors (beheaded Mexicans in America's deserts!), run a few scare clips (a mosque at Ground Zero!) and make yesterday's monster seem downright cuddly  and today's seem downright deadly. "In general, we're not always super politically educated, so people are getting their information from people who pare it back for them," says Dunham.

That, surely, is true. And that, surely, can't be good for us. Playing with cultural matches like this may yield short-term political gain, but you can't control the sparks that pop free  or the wildfires they ignite. It's a simple safety lesson we teach our kids, and it's one our political classes would do well to heed themselves.